催化学报 ›› 2009, Vol. 30 ›› Issue (6): 537-542.

• 研究论文 • 上一篇    下一篇

掺钡纳米氧化镁负载钌基氨合成催化剂的还原性能及其机理

霍超,夏庆华,骆燕,杨霞珍,刘化章   

  1. 浙江工业大学化学工程与材料学院, 浙江杭州 310032
  • 收稿日期:2009-06-25 出版日期:2009-06-25 发布日期:2013-03-22

Reduction Performance and Mechanism of Ba-Doped Nano-magnesia-Sup-ported Ru Catalysts for Ammonia Synthesis

HUO Chao*, XIA Qinghua, LUO Yan, YANG Xiazhen, LIU Huazhang   

  1. College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, Zhejiang, China
  • Received:2009-06-25 Online:2009-06-25 Published:2013-03-22

摘要: 采用超声共沉淀法制备了掺钡纳米氧化镁负载的钌基氨合成催化剂 Ru/Ba-MgO 和 Ru/La-Ba-MgO. 催化剂中 Ba 是以 BaCO3 的形式存在于 MgO 载体中, 使用时需还原活化为 BaO. 采用升温-恒温-升温阶梯式的还原程序考察了还原条件对催化剂还原性能及催化性能的影响, 并利用透射电镜、X 射线衍射、H2 脉冲化学吸附、热重及程序升温还原等分析手段, 对催化剂在氢气气氛中的还原机理进行了探讨. 结果表明, 催化剂中 BaCO3 的热稳定性及 Ru 粒子是否聚结长大是影响催化剂活性的主要因素. 在氢气气氛中, Ru/Ba-MgO 催化剂的还原过程存在偶合反应, Ru 的存在可加速该偶合反应的进行, 进而促进催化剂还原, 提高其催化活性.

关键词: 钡, 纳米氧化镁, 钌, 负载型催化剂, 氨合成, 还原性能, 偶合反应

Abstract: The Ru/Ba-MgO and Ru/La-Ba-MgO catalysts were reduced due to the BaO acting as the most activate form. The effect of reduction conditions on the catalytic performance of the ruthenium catalysts was studied by a heating-holding-heating reduction program, and the reduction mechanism of ruthenium catalysts under hydrogen atmosphere was discussed.

Key words: barium, nano-magnesia, ruthenium, supported catalyst, ammonia synthesis, reduction performance, coupling reaction